MY DEAR GEORGE, Mrs Jebh's account of the twins and the way she puts it, is most striking. How one wishes one could have such a case under close examination. A single instance verified in a large number of particulars would carry such immense weight. Thanks very many for sending it to me.

What a pleasant Autumn you have before you. We shall not meet first, as we leave Town to-day week (Aug. 8) to stay with Judge Grove and thence on Aug. 24 we go abroad to the Tyrol.

I am rejoiced at the fair promise of all your earth axis work and especially at the fact that

you can do so much without being upset by it. What laborious work it must have been.

I have just left Hooker at the Club, very matrimonial-looking, studying the Bravo case*.

Ever yours, FRANCIS GALTON.

To GEORGE DARWIN, ESQ.

42, RUTLAND GATE, S.W. January 5, 1877.

MY DEAR GEORGE, How wonderfully inventive you are. I am most anxious to learn your plan about the curve-drawing.

May I venture to trouble you with a request, not a great one? It is to look through a short, clearly written (orthographically, I mean) memoir on "Typical Laws of Descent" which I propose sending to the Royal Society and which would occupy four to five pages of the Proceedings, and tell me if it is sufficiently intelligible.

You did me real good service in burking my memoir of last year. This is certainly very much better than that, but tell me-is it good enough? I will send it at once, if you will have it. Affectionately yours, FRANCIS GALTON.

P.S. Pencil anything you like on it. If possible I want to send it in soon to the Royal Society so as to be read before my February 9 lecture. To GEORGE DARWIN, ESQ.

42, RUTLAND GATE, S.W. January 12, 1877.

MY DEAR GEORGE, How can I thank you sufficiently. I am aghast at the trouble my unlucky memoir gives, and at the great pains you have taken to put clearness into it. I will certainly adopt your suggestions generally and rewrite the thing.

Let me mention an illustration of one of the principles (Family Variation), which I think may interest you. You recollect that apparatus of mine with the shot;-well, suppose I want to show by a modification of it, how it comes to pass that when the ordinates of an exponic t

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mountain subside, each of them, into an exponic hillock, as in the sketch, the sum of the hillocks is an exponic curve of larger modulus.

In I (see p. 466), I pour shot, and it makes an exponic heap at the bottom. In II, I have cut the apparatus across at AB, and have interposed a row of vertical compartments with trap door bottoms that I can pull out and in A B to form a temporary landing for the shot, when I so desire. If these are open, the shot falls through and of course makes an exponic

mountain at the bottom of II exactly as it did in I. But if they A

~ I I I B`

are closed, they intercept the shot and an exponic mountain (of less

A famous trial of that day; Mrs Bravo was tried for poisoning her husband.

t I do not remember Galton using this word elsewhere as an abbreviation for "exponential." It seems itself slightly "out of place.